Abstract 3977: Neutrophils fertilize the pre-metastatic omental niche in ovarian cancer

Abstract

Abstract More than 60% of ovarian cancer patients present with peritoneal carcinomatosis that almost always involves the omentum, a fat pad that suspends from the stomach. However, the mechanisms that promote the tropism of ovarian cancer cells for the omentum are poorly understood. Because the omentum is the major peritoneal conduit and reservoir for immune cells, we hypothesized that immune cells control the propensity of ovarian cancer cells to implant on the omentum. In this study, we evaluated changes in immune cell populations in the omentum and in other visceral fat pads in the peritoneal cavity in mouse xenograft models of ovarian cancer. Intriguingly, the proportion of neutrophils was observed to dramatically increase in the omentum prior to tumor cell implantation at this site. On the other hand, the proportion of neutrophils did not substantially increase in other visceral fat pads. Furthermore, the proportion of macrophages did not significantly increase in any of the fat tissues prior to tumor cell implantation. Collectively, these findings raise the possibility that early recruitment of neutrophils to the pre-metastatic omental niche promotes a microenvironment that is conducive to ovarian cancer cell implantation at this site. Citation Format: WonJae LEE, Honami Naora. Neutrophils fertilize the pre-metastatic omental niche in ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3977. doi:10.1158/1538-7445.AM2017-3977